Contrast-enhanced ultrasound (“CEUS”) imaging can be used to observe perfusion according to different techniques, but many of these techniques can produce only relative observations. These techniques often collect dynamic data over a single tissue plane, so that the results are highly dependent on the orientation of the ultrasound probe and the results for the single tissue plane do not accurately reflect global perfusion (e.g., of an organ). Other techniques that map perfusion over a volume are accurate under controlled conditions, but are application limited due to a lack of an analytic approach that is valid and accurate in three dimensions.